Optical measurement devices require accurate aligning of sample towards the optics side of the device and the optical detectors. Any slight deviation from the proper alignment results in erroneous measurement, inaccurate data, and sometimes complete breakdown of the device. Thus, any optical device requires proper positioning and alignment of all the relevant parts of the device, which positioning and alignment has to be maintained throughout the operating life of the device. However, in practical situations, this may not be possible as there is bound to be some shake and movement during use. Hence, there needs to be some manner of determining any misalignment or other deviations from perfect positioning so that accuracy of the measurements is not lost. Further, any additional components for this purpose cannot add too much to the cost of the device in general. Also, variations in sample measurements conducted at different time periods, and those conducted using different instruments are common. A facile manner to deal with the variations is a dire need in the art.